Hi, I had a battery error warning today while flying my p4 but I can't find any information on why I got the error. This is the error I got, "Battery Error. Return home soon. View the checklist after landing."
I checked battery levels after landing and they were all the same and I still had 40% battery left.
I haven't had a chance to fly with my other two batteries yet to see if I get the same warning or not to rule out the P4 as the source, any help would be appreciated.

One or more of your battery cells deviation is too high. Be very carefull, I sugest you to stop using this battery. Check the flight log. No matter what precent of the charge is left in the battery.

Hi Vendex, I uploaded my flight log to Airdata and there was over a minute of deviation which I suspected to be the reason for the error. Thanks for your response.

Does the battery error message remain after re-starting the aircraft? Please try to fully discharge the battery and recharge fully again to see whether it helps.

DJI Susan Posted at 2017-11-8 23:55
Does the battery error message remain after re-starting the aircraft? Please try to fully discharge the battery and recharge fully again to see whether it helps.

Hi Susan, it’s not there after restarting but after a full charge it showed up again today on a low load flight and said “broken cell” in the status menu in the DJI 4 App.  I will try what you suggested and hover it close to the ground to see if I get the error again.

This is the battery in question, it’s strange how cell 3 is much higher as if cell 2 is compensating for cell 3.

That is very odd, take the average of cell 2 and 3 and it's in line with cell 1 and 4. Did you fully discharge that battery before recharging it....like leave it in the drone with motors spinning (no props on) until it shuts down on it's own, then recharge. It might recover from a rebalanced charge...if not, then it's a gonner!!

Rudders Posted at 2017-11-9 01:48
That is very odd, take the average of cell 2 and 3 and it's in line with cell 1 and 4. Did you fully discharge that battery before recharging it....like leave it in the drone with motors spinning (no props on) until it shuts down on it's own, then recharge. It might recover from a rebalanced charge...if not, then it's a gonner!!

I’ve did that this morning and put it on charge, I will test it when I get home this afternoon.

So I did a full discharge and recharge and after a test flight the battery had no warnings, there were two deviations of 0.078 on cell 1 but that’s it. So for now the full discharge was enough to rebalance the cells.
Thanks for the help guys, I will continue to monitor this battery after every flight to see if it maintains a good balance and if not I will retire it.

Good result. Fingers crossed that should be it sorted. Do the same to your batteries every 20 or so charge cycles as they do go out of whack sometimes with the calibration...fickle things they are. If it does go wonky again, keep it for testing/doing updates etc. Also do not leave them fully charged between missions for more than say 4 or 5 days. Set them to auto discharge incase you forget. Then charge before setting off for a days flying.

Rudders Posted at 2017-11-10 01:09
Good result. Fingers crossed that should be it sorted. Do the same to your batteries every 20 or so charge cycles as they do go out of whack sometimes with the calibration...fickle things they are. If it does go wonky again, keep it for testing/doing updates etc. Also do not leave them fully charged between missions for more than say 4 or 5 days. Set them to auto discharge incase you forget. Then charge before setting off for a days flying.

I’ve done this in the past to help with capacity but I will be doing it more often for this as well.
I did the other 2 batteries today as well, I’m really glad it’s sorted as here in Australia a new battery is between $212 n $260 dollars which is a lot of money.

mic75 Posted at 2017-11-9 01:22
This is the battery in question, it’s strange how cell 3 is much higher as if cell 2 is compensating for cell 3. [view_image]

Out of curiosity, did you happen to get the battery wet?  Or maybe fly though a cloud or humid environment?  I have a hard time actually believing that the reported voltages were actually that far out of whack, and that a battery cycle corrected that much of an imbalance.  It almost seems as though the cells were actually in balance the whole time, but there was some PCB board contamination going on that caused the improper measurement.  I work with electronics quite a bit as an electrical engineer, and this one intrigues me! . I would have thought that the PCBs inside the battery are conformal coated like the boards in the drone.  That way moisture wouldn't be able to affect any high resistance voltage dividers.
You were flying...meaning that there was at least 10+ amps being drawn from the battery.  I do not believe that cell #3 could have a loaded 4.5V voltage on it.

Do you have any log data more recently that shows the cells in balance?

Mugrunty Posted at 2017-11-10 08:28
Out of curiosity, did you happen to get the battery wet?  Or maybe fly though a cloud or humid environment?  I have a hard time actually believing that the reported voltages were actually that far out of whack, and that a battery cycle corrected that much of an imbalance.  It almost seems as though the cells were actually in balance the whole time, but there was some PCB board contamination going on that caused the improper measurement.  I work with electronics quite a bit as an electrical engineer, and this one intrigues me! . I would have thought that the PCBs inside the battery are conformal coated like the boards in the drone.  That way moisture wouldn't be able to affect any high resistance voltage dividers.
You were flying...meaning that there was at least 10+ amps being drawn from the battery.  I do not believe that cell #3 could have a loaded 4.5V voltage on it.

No clouds and battery has never been wet, I also find it strange that cell 3 is reading high and cell 2 so low, it's almost like it's not reading the cells properly. I used that battery again to and it's worse now, it's seams to be ok if I fully discharge the battery like yesterday, but todays flight was a recharge from about 20%.
I'm fully discharging it now and after I charge it I will hover it low to the ground and see what it does, I think I will stop using it regardless as it's just not worth the risk.
when I flew it home I was monitoring the cell and even at low speed and low load cell 2 was dropping to 3 volts, so I was very glad I got it home without crashing.
The first flight when the error first showed up I was climbing to 500m in sport mode and the amps hit 25+ but todays flight saw no where near that and the cells were all level after I had landed.

So I did a full discharge but this time I got the error again.

Very good idea is to stop using that battery

If it said "broken cell" then it's not likely the battery can be repaired with a full discharge.  

A full discharge is a process.  You can't just discharge it.  You're not going to see an improvement by discharging it and looking at the cells.  

Here is the process:

1)  Be sure you are starting with a fully charged battery.

2)  Discharge the battery down to whatever percentage you have decided per instructions, manual, advice, your opinion, or whatever - generally in the 5-8% range.

3)  Bring the battery back up to fully charged.

Now check the cell balance.  It may be better balanced or it may not.  

Know that the full discharge process will likely permanently rob some mAh from your battery.

Good luck.  

Mark The Droner Posted at 2017-11-11 04:47
If it said "broken cell" then it's not likely the battery can be repaired with a full discharge.  

A full discharge is a process.  You can't just discharge it.  You're not going to see an improvement by discharging it and looking at the cells.  

Was just following DJI Susan’s suggestion, also it worked the first time and was worth a try.

Her solution included "recharge fully."  

Vendex Posted at 2017-11-11 04:01
Very good idea is to stop using that battery

Yes that goes without saying, it will now become a power bank for charging iPhones n iPads.

Mark The Droner Posted at 2017-11-11 04:47
If it said "broken cell" then it's not likely the battery can be repaired with a full discharge.  

A full discharge is a process.  You can't just discharge it.  You're not going to see an improvement by discharging it and looking at the cells.  

I wasn’t fully discharging to check cells, I discharged then fully charged and checked cells from full and while I was flying it. I don’t think it’s actually a problem with cells, I think it’s in the hardware reading the cells. Cell 2 was dropping down to 3.03 volts and cell 3 was climbing up to 4.35 volts at the same time and then they would settle back to nearly an even state. 4.35 volts is above my full charge starting voltage. Also the cells don’t charge that fast, especially not without considerable heat and the battery was only warm to touch.
I don’t think this smart battery is very smart anymore.

The new moto is: Leave the battery, save the craft :-)

mic75 Posted at 2017-11-11 05:10
...Cell 2 was dropping down to 3.03 volts and cell 3 was climbing up to 4.35 volts at the same time and then they would settle back to nearly an even state. ...

Do you know what happens when that cell at 3.03 volts drops down to 2.99 v?  

Mark The Droner Posted at 2017-11-11 04:56
Her solution included "recharge fully."

Yes and I did that, I’ve done this before to help with capacity.

Mark The Droner Posted at 2017-11-11 05:48
Do you know what happens when that cell at 3.03 volts drops down to 2.99 v?

I know that over discharging a LiPo causes it to swell up and in some cases catch fire.
I got a low voltage warning at 3.03 and told to land but beyond that enlighten me, fall out of the sky maybe or in this case fall 30cm to the ground.

When any cell drops at or below 3.0 volts, the entire battery shuts off.  

mic75 Posted at 2017-11-11 05:10
I wasn’t fully discharging to check cells, I discharged then fully charged and checked cells from full and while I was flying it. I don’t think it’s actually a problem with cells, I think it’s in the hardware reading the cells. Cell 2 was dropping down to 3.03 volts and cell 3 was climbing up to 4.35 volts at the same time and then they would settle back to nearly an even state. 4.35 volts is above my full charge starting voltage. Also the cells don’t charge that fast, especially not without considerable heat and the battery was only warm to touch.
I don’t think this smart battery is very smart anymore.

I'd agree.  The voltage measuring circuit seems to be intermittently measuring wrong values.  Very interesting.

It seems that the battery has been damaged already. If the battery is still in the warranty period, you can contact the support for further assistance.

I sent mine to DJI for warranty repair over 6 mouths ago. Still waiting?

DJI Susan Posted at 2017-11-14 02:30
It seems that the battery has been damaged already. If the battery is still in the warranty period, you can contact the support for further assistance.

It’s out of warranty thanks Susan.

fans52cfa4bf Posted at 2017-11-14 02:40
I sent mine to DJI for warranty repair over 6 mouths ago. Still waiting?

Wow 6 months

Mark The Droner Posted at 2017-11-11 07:05
When any cell drops at or below 3.0 volts, the entire battery shuts off.

Battery protection to stop over discharge, they turn into nasty little buggers when you run them to low.

fans52cfa4bf Posted at 2017-11-14 02:40
I sent mine to DJI for warranty repair over 6 mouths ago. Still waiting?

Sir, could you tell us your case number? I'll check the exact status and keep follow up for you.

mic75 Posted at 2017-11-14 14:32
It’s out of warranty thanks Susan.

Sorry to hear this.

mic75 Posted at 2017-11-11 05:10
I wasn’t fully discharging to check cells, I discharged then fully charged and checked cells from full and while I was flying it. I don’t think it’s actually a problem with cells, I think it’s in the hardware reading the cells. Cell 2 was dropping down to 3.03 volts and cell 3 was climbing up to 4.35 volts at the same time and then they would settle back to nearly an even state. 4.35 volts is above my full charge starting voltage. Also the cells don’t charge that fast, especially not without considerable heat and the battery was only warm to touch.
I don’t think this smart battery is very smart anymore.

Have you checked the connectors?
Perhaps a gently wipe off with a small wire brush can do miracles. Or as it is already out of warranty open it and check internal connections.

KedDK Posted at 2017-11-19 23:16
Have you checked the connectors?
Perhaps a gently wipe off with a small wire brush can do miracles. Or as it is already out of warranty open it and check internal connections.

Yeah I thought about pulling it apart to have a look but I’ll just use it as a power bank now, I will check external connectors though, thanks for suggestion.

I have this problem on m,y inspire 1 cells are 3.93 4.02 3.99 4.00 4.04 4.11
where can I check the check list

Ceeps Posted at 2018-9-8 05:07
I have this problem on m,y inspire 1 cells are 3.93 4.02 3.99 4.00 4.04 4.11
where can I check the check list

Hi Ceeps, in the DJI app if you can click on the three dots in the top right corner then the three dots down the bottom which is general settings, scroll down to warnings and there will be information in there about any warnings that appeared on your screen during your flight.
Alternatively you can can go to a website called www.airdata.com and upload the log from your flight with the errors and get a more detailed view of your battery information as well as lots of other cool stuff.